Nest box design for the study of diurnal raptors and owls is still an overlooked point in ecological, evolutionary and conservation studies: a review

The use of artificial nest boxes has led to significant progress in bird conservation and in our understanding of the functional and evolutionary ecology of free-ranging birds that exploit cavities for roosting and reproduction. Nest boxes and their improved accessibility have made it easier to perform comparative and experimental field investigations. However, concerns about the generality and applicability of scientific studies involving birds breeding in nest boxes have been raised because the occupants of boxes may differ from conspecifics occupying other nest sites. Here, we review the existing evidence demonstrating the importance of nest box design to individual life-history traits in three falcon (Falconiformes) and seven owl (Strigiformes) species, as well as the extent to which publications on these birds describe the characteristics of exploited artificial nest boxes in their Methods sections. More than 60% of recent publications did not provide any details on nest box design (e.g. size, shape, material), despite several calls > 15 years ago to increase the reporting of such information. We exemplify and discuss how variation in nest box characteristics can affect or confound conclusions from nest box studies and conclude that it is of overall importance to present details of nest box characteristics in scientific publications.